1. Field of the Invention
The present invention relates to a device and method for reducing the area of a transdermal patch. More specifically, the invention provides a sizing template used to reduce the area of a transdermal patch by a desired percentage.
A transdermal patch is a patch containing a drug that, when applied to the skin, delivers the drug through the skin to the patient. Although the concept appears simple, the method of transferring a drug through the skin via a transdermal patch is quite complex. Even so, transdermal patches are currently used for delivering numerous drugs, including nitroglycerine, isosorbide dinitrate, scopolamine, clonidine, progesterone, estradial, nicotine, and fentanyl. Of particular interest to the present invention are nicotine transdermal patches used for delivering nicotine in connection with therapy for smoking cessation.
Several types of transdermal patch designs are now in commercial use. A summary of these designs is given in Gary W. Cleary, "Transdermal Drug Delivery," Cosmetics and Toiletries, May 1991, which is herein incorporated by reference. Of particular importance to the present invention are transdermal patches having a "solid-state" design where each patch has a defined surface area, and the amount of drug delivered to the patient corresponds to the surface area of the patch. Solid-state design also allows the patches to be cut into smaller patches without altering the pharmacokinetic delivery profile, i.e. amount of drug delivered per unit area. Examples of patches with solid-state designs are Nicotrol.RTM., manufactured by Cygnus Therapeutic Systems, supplied by Kabi Pharmacia AB, and distributed by Parke-Davis, and Nicoderm.RTM., distributed by Marion Merril Dow.
The use of solid-state design patches is thus advantageous when used in connection with a therapeutic system where the patient must have either tailored dosages or tapered dosages of the prescribed drug. Tailoring the dosage of the prescribed drug can be accomplished by using a number of differently sized patches singly or in combination to ensure the patient receives the appropriate amount of drug. While patches will often be available in at least several sizes, the patches needed to obtain the prescribed dosage will often differ from the available sizes. In such cases the required surface area may be obtained by cutting the patch to reduce its surface area by a desired percentage, where the delivered drug dosage is reduced by the same percentage.
One problem that can occur with either tailoring or tapering in the manner just described is that the patches may be cut to an incorrect size. This will typically occur when a patient, without proper assistance from medical personnel, tries to reduce or alter the size of the patch. While it would be possible for the patient to visit the doctor's office to have the patches cut, such visits will be inconvenient to the patient and inefficient for the doctor.
A desired solution to such a problem is to provide a template to enable a patient to cut a single sized patch from a larger commercially available patch to obtain the necessary patch size as prescribed by the doctor. However, a template designed only to reduce one size of patch would be incompatible for use with commercially available patches which are available in a number of various patch sizes. Further, if a patient were given such a template by the doctor with instructions to reduce the area of one particular sized patch to be used in combination with another (original sized) patch to obtain the necessary dosage, the patient would have difficulty in determining which size of patch the template was to be used with. In such a case, the patient may mistakenly use the template to cut the patch that was not intended to be cut, while the patch that was to be reduced in size was not. Even if the template indicated which size of patch were to be cut, the patient would still have difficulty in determining the correct patch to be cut because commercially available patches are not typically marked with a size indication.
A method and a device are therefore needed to simply and easily reduce the area of a transdermal patch to allow a patient to either tailor or taper their dosage of the prescribed drug within the patch. The method and device should be economical for the patient so that the patient may use only one prescribed set of patches without having to purchase new patches of differing sizes for each different prescribed dosage.
2. Description of the Background Art
U.S. Pat. No. 1,827,375 describes a template to position an address on letter head to ensure that, when folded an inserted into an envelope, the address will be visible through a window in the envelope.
U.S. Pat. No. 1,624,150 describes a gauge used to measure the thickness of a piece of lumber.
U.S. Pat. No. 1,380,187 describes a measuring and gauging device particularly useful for dressmakers. One use of the device is for gauging the evenness of the hang of a skirt.
U.S. Pat. No. 2,834,522 describes a tool for manually forming pleats for clothing.
U.S. Pat. No. 4,736,525 describes a floor square for use in squaring and marking a ledger notch in the end of a floor joist and for use in marking the intended position of a ledger on a girder.
U.S. Pat. No. 4,266,388 describes a template for positioning an array of overlapping shingles on a roof.
U.S. Pat. No. 2,981,005 shows a bolt gauge to measure bolt diameters and lengths.
U.S. Pat. No. 3,201,873 describes a gauge block with a graduated stepped gauging edge for engagement with a mating part of a machine such as a saw or router to establish a desired dimension.
Popular Science, 20-IN-1 Shop Guide, .COPYRGT.1966 shows a "shop" template used to measure the length and diameter of screws, nuts, bolts, drill bits, nails, etc.